DeCaff2007
I'm Awesome
Sorry I keep posting non-GMT400 questions, HOWEVER, there's a serious lack of support (meaning no forums, and I don't do the FB garbage) for what I'm working on.
Long story short, I'm converting my Wife's 67 Buick Special from a junk 2bbl carb, to a Holley Sniper EFI... in hopes of a very large increase in reliability.
So, here's the skinny. The [absolutely worthless] factory fuel system had to be junked and replaced with this: https://www.efisystempro.com/fuel-s...odules-chevelle-malibu-el-camino-64-67-12-302.
Fuel pump is wired into a relay that comes with the EFI harness. A switched 12.5V triggers the relay and that fires the pump. Easy, right? Not really. I'm only getting 11.8 ~ ish volts out of a brand spanking new AC Delco battery. I thought, ok, maybe it's a bad relay so I tested that separately. The relay is fine.
With that, since I can't get the relay to trigger when it's in the car, I JUMPERED the two relay terminals (in the wiring harness) to act like a relay that's turned on. Fuel pump INSTANTLY fired up and pegged my fuel pressure gauge past its 100 psi max reading.
How is that possible? There's a regulator in the pump and on the EFI unit. Can a fuel pump even go that high? I don't want to go returning a very expensive and very proprietary fuel pump if I don't have to. Maybe a bad fuel pump tester? The last time I used that tester was to verify the correct PSI for the 2bbl carb on this same vehicle. It worked fine, although it only needed 5 PSI, which it held nicely.
I'm at a loss here. Can an electric fuel pump seriously support 100+ PSI?
Long story short, I'm converting my Wife's 67 Buick Special from a junk 2bbl carb, to a Holley Sniper EFI... in hopes of a very large increase in reliability.
So, here's the skinny. The [absolutely worthless] factory fuel system had to be junked and replaced with this: https://www.efisystempro.com/fuel-s...odules-chevelle-malibu-el-camino-64-67-12-302.
Fuel pump is wired into a relay that comes with the EFI harness. A switched 12.5V triggers the relay and that fires the pump. Easy, right? Not really. I'm only getting 11.8 ~ ish volts out of a brand spanking new AC Delco battery. I thought, ok, maybe it's a bad relay so I tested that separately. The relay is fine.
With that, since I can't get the relay to trigger when it's in the car, I JUMPERED the two relay terminals (in the wiring harness) to act like a relay that's turned on. Fuel pump INSTANTLY fired up and pegged my fuel pressure gauge past its 100 psi max reading.
How is that possible? There's a regulator in the pump and on the EFI unit. Can a fuel pump even go that high? I don't want to go returning a very expensive and very proprietary fuel pump if I don't have to. Maybe a bad fuel pump tester? The last time I used that tester was to verify the correct PSI for the 2bbl carb on this same vehicle. It worked fine, although it only needed 5 PSI, which it held nicely.
I'm at a loss here. Can an electric fuel pump seriously support 100+ PSI?